In addition to our many Year in Review posts, we suggest you take a look at Fimoculus's massive collection of 2010 year-end lists. The List of Lists aggregates hundreds of lists enumerating the year's best in art, architecture, cars, books, music, film, design, games, politics, science, and much, much more, from all sorts of sources (great and small).
Before you start sifting through the mounds of information, be warned that it will likely consume the better half of your day.
You can also submit your own list suggestions here.